With an increase in telecommunication demands, improved throughput of switching devices such as a layer 2 switch and a router, or in other words, improved throughput of packet switching devices that switch packets is expected. In order to improve the throughput, improvement in the scheduling function of managing traffic by controlling readout of packets from queues is being discussed.
For example, Japanese Laid-open Patent Publication No. 2001-223740 discusses that a proper grading is set on the basis of statistical observation information in a deficit round robin (DRR) method. Japanese Laid-open Patent Publication No. 2005-33408 discusses that the precision in a band of an algorithm that maintains band control is maintained in a case where data is read out from a queue that is selected through a different algorithm.
Japanese Laid-open Patent Publication No. 2005-286383 discusses that the processing time for accessing an external memory is reduced by scheduling packets in units of fixed segment lengths in each queue that store packets. U.S. Pat. No. 7,990,858 discusses that in a configuration in which an input controller and an output band controller are interconnected through fabric, the input controller outputs packets to the output band controller through the fabric on the basis of credits obtained from the output band controller in response to a request.